Conventionally, a technology exists where by holding a prepaid card, on which an authentication code corresponding to a conductor/nonconductor arrangement pattern is recorded, against an electronic device (for example, a smartphone) equipped with a touch panel, the arrangement pattern of the conductor and the nonconductor is detected by the touch panel, and based on the detection result, the authentication code is recognized by the electronic device (see Japanese Patent Application Laid-Open (JP-A) No. 2004-102798).